Poor Car Assembling

C-NET VEHICLE FITMENT AND REPAIR CENTRE, Service was pathetic. Audi A4 2015 was given to them for a coolant leak and they confirmed it's water pump leakage and took 7 days to get a correct water pump and finally after setting up the water pump i again had the same problem again when i took the car again back to them i have been told its because of other pipe leakage and who lot of other things also needs to be replaced to have a second opinion i took my car to Grayston Audi showroom and i have been advised that whoever worked on my car did the poor assembling which caused the issue for which i have all the recorded evidences. When i called the guy at C-Net to explain the same he was so rude and was arguing he doesn't want to speak to me as if we had personal rivalry.